Discovery of natural infection by Metagonimus hakubaensis Shimazu, 1999 (Trematoda: Heterophyidae) in Japanese water shrews (Chimarrogale platycephala) in Japan.

A total of 611 preserved adult Metagonimus spp. specimens recovered from 32 of 53 Japanese water shrews (Chimarrogale platycephala) that had previously been collected in Aomori Prefecture between June 1994 and August 1996, were examined in this study. Morphological examination revealed that 603 of these flukes were identical to M. hakubaensis Shimazu, 1999, and that the others were M. takahashii Suzuki, 1930 (n=4), M. otsurui Saito et Shimizu, 1968 (n=2), and M. miyatai Saito et al., 1997 (n=2). Each of the 32 Japanese water shrews infected with M. hakubaensis contained between 1 and 83 flukes. This is the first record of the natural final host for M. hakubaensis, since this fluke species was described.